Measurement of the moments of the hadronic invariant mass distribution in semileptonic B decays
Journal
Physical Review D - Particles, Fields, Gravitation and Cosmology
Journal Volume
71
Journal Issue
5
Pages
1月9日
Date Issued
2005
Author(s)
Acosta, D. et al. (The CDF Collaboration)
Abstract
Using 180 pb -1 of data collected with the CDF II detector at the Tevatron, we measure the first two moments of the hadronic invariant mass-squared distribution in charmed semileptonic B decays. From these we determine the nonperturbative Heavy Quark Effective Theory parameters Λ and λ 1 used to relate the B meson semileptonic branching ratio to the CKM matrix element |V cb|. For a minimum lepton momentum of 0.7 GeV/c in the B rest frame we measure the first two moments of the D** → D (*)π component to be 〈m D** 2〉 = (5.83 ± 0.16 stat ± 0.08 syst) GeV 2/c 4 and 〈(m D** 2 - 〈m D** 2〉) 2〉 = (1.30 ± 0.69 stat ± 0.22 syst) GeV 4/c 8. Combining these with the discrete mass terms from the D and D* mesons, we find the total moments to be 〈M Ξc 2〉 - m̄ D 2 = (0.467 ± 0.038 stat ± 0.068 syst GeV 2/c 4 and 〈(M Ξc 2 - 〈M Ξc 2〉) 2〉 = (1.05 ± 0.26 stat ± 0.13 syst) GeV 4/c 8, where m̄ D is the spin-averaged D mass. The systematic error is dominated by the uncertainties in the world-average branching ratios used to combine the D, D*, and D** contributions. The analysis makes no assumptions about the shape or resonant structure of the D** → D (*)π invariant mass distribution. © 2005 The American Physical Society.
Type
journal article